Tricopter build: Yaw control
I've gone with a 1/4" carbon fibre rod inserted and glued into the pine arm. The last 40mm of the arm is left to rotate freely on the CF rod. See this post for further details.
**This configuration will prove to be "not up to it" when it flips on a test flight, the screws in the control arm caused it to split and break free. I'm about to redesign and build something new for yaw control.
Cyberquad for search and rescue
The Melbourne Metropolitan Fire Brigade are evaluating a Cyberquad UAV for potential use in search, rescue and fire spotting operations. A couple of MFB guys brought the UAV down to the LDMFA Field for our Christmas meeting and while it didn't do any flying demonstration we got a chance to see the FPV goggles, thermal imaging camera, remote monitor and gyro tracking camera working.
This UAV has a standard definition colour camera as well as a thermal infra-red camera that are stabilised by a gyro so the cameras will always point at a target no matter the wind conditions. The guys say it copes with 30-40 knot winds and will remain quite stable although battery life is reduced because it has to work much harder to stay in position. It also has goggles and a remote screen for FPV flight.
The MFB may use it for indoor and outdoor applications. Indoor could include search operations through dangerous or difficult to access locations. Apparently a skilled operator can navigate through the width of a door quite easily. While outdoor, the UAV could be used for firespotting or reconnaissance where a crew on the ground might be surrounded by bush. Where the SD colour camera can't penetrate a forest tree top canopy, switching to the thermal camera makes the tree tops disappear and any fire below is easily seen.
Tricopter build: Mounting the motors
The base is cut from 1/4" ply and the arms are 12mm x 12mm Tas oak about 20" long. Excuse my interchanging metric and imperial units but thats what you get building from forums in the US. I'm using a method described on the mongrelgear.com.au site for mounting the motors which is simply cable ties and a bit of glue. I found with the spacing of the motor mount holes and the bend radius of the ties, I needed to insert some carbon fiber rods to take up the slack on the cable tie. By the time it's all finished, the motors are mounted securely, quickly and easily.
Flite test: how to add lights
So far I've built the rcpowers.com extra 300 foamy and added a HK401B gryo and I still haven't flown it. Maybe I should add some lights just for good luck
Tricopter build: The parts arrive
The main box of goodies has arrived from HobbyKing. The first thing I'm going to do is solder all the connections on the motors and ESCs. I found this handy little guide that mongrelgear provide with their tri-copter kits.
The motors arrive as shown on the left in the photo below (no connections). You need to solder the connectors and apply some heatshrink wrap.
Tricopter motor from Hobbyking
rcpowers.com extra 300: Gyro install
I haven't even flown version 2 of the rcpowers.com extra 300 foamy but what better plane to try out the hobbyking 401B Gyro on. I had problems getting it to work with the Fly-Dream 2.4Ghz receiver so I swapped over to a JR 36MHz synthesized Rx and it worked a treat.
Tricopter build: Yaw mount
The method I'm going to try for the yaw mount is to drill as far into the main arm as my drill bit will go and insert a 5mm carbon rod. Then drill through the remaining block, about 1.5" long which will be able to pivot on the carbon rod. The fit on the rod is snug but not too tight. The hardest part was drilling a vertical hole in the centre of the 12mm x 12mm Tas Oak arm without going crooked and drilling out the side.
Tricoper build: The frame
The frame is cut from 1/4" ply and the arms from 12mm x 12mm Tas Oak. I've used 1/4" metal bolts for now but they'll probably be swapped for nylon down the track. The hardest part was using the jigsaw to cut the base frame around the smaller curves near the arms.
Tricopter build: Parts List
The tricopter bug has bitten and I've ordered the parts to build one. Technically it's a present from Santa so I might have to wait until after Christmas to put it together.
I'm taking direction form two main sources;
- http://www.rcexplorer.se/projects/tricopter/tricopter.html
- http://www.rcgroups.com/forums/showthread.php?t=1142429
Trying to order the exact same parts from either build is tough as a lot of the parts are on backorder at hobbyking () so I'm hoping what I have ordered is suitable.
For those not familiar with Tricopters, here's a video of one someone else has built and successfully flown.
3 x Motors - 2213N 800Kv Brushless motor for AXN Floater-Jet
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=8622
3 x Hobbyking SS Series 15-18A ESC
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=6456
4 x Hobby King 401B AVCS Digital Head Lock Gyro
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=10113
2 x GWS EP Propeller (RD-1047 254x119mm) (6pcs/set)
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=10055
1 x GWS EP Propeller (RD-1147 279x119mm) (6pcs/set)
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=10049
1 x Turnigy 380MAX Micro Servo (Metal Gear) 4.1kg / .16sec / 17.4g
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=8760
1 x Turnigy 5A (8-26v) SBEC for Lipo
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=10312
1 x TURNIGY BESC Programming Card
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=2169
1 x ZIPPY Flightmax 2200mAh 3S1P 20C
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=6306
1 x Hobby King Battery Monitor 3S
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=7223
5 x Turnigy Pure-Silicone Wire 14AWG (1mtr) BLACK
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=9679
5 x Turnigy Pure-Silicone Wire 14AWG (1mtr) RED
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=9678
2 x XT60 Connectors Male/Female (5 pairs)
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=9572
2 x Gold Plated Spring Connector 3.5mm (10pair/20pc)
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=4136
Inside the eHawk 1500
The eHawk is about ready to maiden. Inside the fuse I have a JR RS70 receiver velcroed to the side of the fuse, a HobbyKing 15-18A ESC to the other side and a Turnigy 1200mAh 3S Lipo in the middle with velcro on the bottom. I haven't checked the CG yet but it looks like I should be able to move the battery back and forth pretty easily. The trusty old Futaba FF7 36Mhz transmitter will provide control. I included pics of the Futaba Tx and JR Rx just because some people don't know that the two brands will happily work together. Why did I buy the JR Rx if I was using the Futaba Tx? Probably because the Futaba Rxs were too expensive (not that the JR was chickenfeed either).
